MLPAO Transfusion Medicine Advanced Practice 2 â Questions and Answers
Question 1: What is gel column technology (gel test) and how does it work in blood banking?
- A culture method for growing bacteria
- A method using dextran gel-filled microtubes where agglutinated red cells are trapped in the gel while non-agglutinated cells pass through to the bottom (Correct answer)
- A molecular testing method
- A method for freezing blood products
Correct answer: A method using dextran gel-filled microtubes where agglutinated red cells are trapped in the gel while non-agglutinated cells pass through to the bottom
Gel column technology (DiaMed/Bio-Rad) uses microtubes containing dextran acrylamide gel. After incubation, tubes are centrifuged: agglutinated red cells are trapped in the gel matrix (positive result), while non-agglutinated cells pass through to the bottom (negative result). This standardized method reduces subjective interpretation and is widely used for typing, antibody screening, and crossmatching.
Question 2: What is transfusion-related acute lung injury (TRALI)?
- Fluid overload from too much blood
- Acute respiratory distress occurring within 6 hours of transfusion, caused by donor antibodies activating recipient neutrophils in pulmonary capillaries (Correct answer)
- A chronic lung condition from repeated transfusions
- An allergic reaction causing asthma
Correct answer: Acute respiratory distress occurring within 6 hours of transfusion, caused by donor antibodies activating recipient neutrophils in pulmonary capillaries
TRALI is a serious complication characterized by acute bilateral pulmonary edema and hypoxia within 6 hours of transfusion, without other risk factors for acute lung injury. It is caused by donor anti-HLA or anti-HNA antibodies that activate recipient neutrophils in pulmonary capillaries. Risk reduction strategies include using male-only plasma donors.
Question 3: What is the significance of the Duffy blood group system in relation to malaria?
- Duffy antigens have no relation to malaria
- The Duffy antigen Fy(a)/Fy(b) serves as the receptor for Plasmodium vivax; Duffy-negative individuals are resistant to P. vivax malaria (Correct answer)
- Duffy antigens protect against P. falciparum
- Duffy antigens cause malaria
Correct answer: The Duffy antigen Fy(a)/Fy(b) serves as the receptor for Plasmodium vivax; Duffy-negative individuals are resistant to P. vivax malaria
The Duffy glycoprotein (DARC) serves as the receptor for P. vivax merozoite invasion of red blood cells. The Fy(a-b-) phenotype (common in individuals of West African descent due to a GATA-1 binding site mutation) confers resistance to P. vivax malaria. This selective advantage has maintained the high frequency of the Duffy-null phenotype in malaria-endemic regions.
Question 4: What is the role of Canadian Blood Services (CBS) in the Canadian blood system?
- CBS provides blood products only in Ontario
- CBS is responsible for collecting, testing, processing, and distributing blood and blood products across Canada (except Québec, which is served by Héma-Québec) (Correct answer)
- CBS only tests blood for infectious diseases
- CBS is a private for-profit company
Correct answer: CBS is responsible for collecting, testing, processing, and distributing blood and blood products across Canada (except Québec, which is served by Héma-Québec)
Canadian Blood Services (CBS) is the national, not-for-profit blood operator responsible for the collection, testing, processing, and distribution of blood and blood products for all Canadian provinces and territories except Québec (served by Héma-Québec). CBS also manages the national stem cell, organ, and tissue donation programs.
Question 5: What infectious disease testing is performed on all donated blood in Canada?
- HIV testing only
- HIV, Hepatitis B, Hepatitis C, HTLV-I/II, Syphilis, West Nile Virus, and additional tests as required (Correct answer)
- Only bacterial culture
- No testing is performed; donors are screened by questionnaire only
Correct answer: HIV, Hepatitis B, Hepatitis C, HTLV-I/II, Syphilis, West Nile Virus, and additional tests as required
All Canadian blood donations are tested for: HIV-1/2 (antibody and NAT), Hepatitis B (HBsAg, anti-HBc, NAT), Hepatitis C (antibody and NAT), HTLV-I/II (antibody), Syphilis (antibody), and West Nile Virus (NAT). Additional testing (e.g., Babesia, Zika) may be implemented based on risk assessment. Nucleic acid testing (NAT) has significantly narrowed the window period.
Question 6: What is the difference between leukoreduction and irradiation of blood products?
- They serve the same purpose
- Leukoreduction removes white blood cells to prevent febrile reactions, CMV transmission, and HLA alloimmunization; irradiation inactivates residual lymphocytes to prevent TA-GVHD (Correct answer)
- Leukoreduction prevents TA-GVHD; irradiation prevents febrile reactions
- Both are required for all transfusions
Correct answer: Leukoreduction removes white blood cells to prevent febrile reactions, CMV transmission, and HLA alloimmunization; irradiation inactivates residual lymphocytes to prevent TA-GVHD
Leukoreduction (filtration to <5 à 10ⶠresidual WBCs) prevents febrile non-hemolytic transfusion reactions, CMV transmission, and HLA alloimmunization. In Canada, all red cells and platelets are pre-storage leukoreduced. Irradiation (25 Gy gamma) inactivates residual T lymphocytes to prevent TA-GVHD in susceptible patients. They serve different, complementary purposes.
MLPAO Transfusion Medicine Advanced Practice 2
What is gel column technology (gel test) and how does it work in blood banking?